Bird Abundance in Different-Aged Stands of Rimu (

The abundance of birds in three different-aged stands (young, mature, and old) was examined at North Okarito, a lowland rimu (Dacrydium cupressinum) forest in Westland, using 5-minute counts, transect counts, and mist-netting. Most of New Zealand's common forest bird species were present in the study area, with relatively high numbers of brown creeper (Mohoua novaeseelandiae) and New Zealand robin (Petroica australis), and low numbers of kaka (Nestor meridionalis) and yellow- crowned parakeet (Cyanoramphus auriceps). Most insectivorous species were more abundant than expected (from sampling effort) in young and mature stands, the frugivorous New Zealand pigeon (Hemiphaga novaeseelandiae) was more abundant than expected in mature and old stands, and most omnivorous species, viz., bellbird (Anthornis melanura), silvereye (Zosterops lateralis), and tui (Prosthemadera novaeseelandiae), were more abundant than expected in young and old stands. North Okarito Forest provided an important source of seasonal foods (nectar, fruit, and seeds) for frugivorous, omnivorous, and introduced granivorous species, which tended to have greater changes in their seasonal abundance than did insectivorous species. Coupe- logging of old stands will affect all bird species because it will reduce the overall area of standing forest, but it will have a greater impact on the pigeon, bellbird, silvereye, robin, and tui because of their preference for old stands.     

Mutualisms with the wreckage of an avifauna: the status of bird pollination and fruit dispersal in New Zealand

Worldwide declines in bird numbers have recently renewed interest in how well bird?plant mutualisms are functioning. In New Zealand, it has been argued that bird pollination was relatively unimportant and bird pollination failure was unlikely to threaten any New Zealand plants, whereas dispersal mutualisms were widespread and in some cases potentially at risk because of reliance on a single large frugivore, the kereru (Hemiphaga novaeseelandiae). Work since 1989, however, has changed that assessment. Smaller individual fruits of most plant species can be dispersed by mid-sized birds such as tui (Prosthemadera novaezelandiae) because both fruits and birds vary in size within a species. Only one species (Beilschmiedia tarairi) has no individual fruits small enough for this to occur. Germination of 19 fleshy-fruited species, including most species with fruits >8 mm diameter, does not depend on birds removing the fruit pulp. The few studies of fruit removal rates mostly (7 out of 10) show good dispersal quantity. So dispersal is less at risk than once thought. In contrast, there is now evidence for widespread pollen limitation in species with ornithophilous flowers. Tests on 10 of the 29 known native ornithophilous-flowered species found that in 8 cases seed production was reduced by at least one-third, and the pollen limitation indices overall were significantly higher than the global average. Birds also frequently visit flowers of many other smaller-flowered native species, and excluding birds significantly reduced seed set in the three species tested. So pollination is more at risk than once thought. Finally, analyses of both species numbers and total woody basal area show that dependence on bird pollination is unexpectedly high. Birds have been recorded visiting the flowers of 85 native species, representing 5% of the total seed-plant flora (compared with 12% of those with fleshy fruit) and 30% of the tree flora (compared with 59% with fleshy fruit). A higher percentage of New Zealand forest basal area has bird-visited flowers (37% of basal area nationally) than fleshy fruit (31%). Thus, bird pollination is more important in New Zealand than was realised, partly because birds visit many flowers that do not have classic ?ornithophilous? flower morphology.     

Fruit size preference in the New Zealand pigeon (Hemiphaga novaeseelandiae)

Abstract We investigated whether the New Zealand pigeon Hemiphaga novaeseelandiae (Columbidae) exhibits size‐based preferences for fruits. We tested the hypothesis that in small‐fruited species, pigeons would prefer larger fruits, but in larger‐fruited species, this preference would reverse as the pigeons become increasingly limited by their gape size. We collected undispersed fruits and bird‐dispersed seeds of 10 plant species, some over several sites or years (13 datasets in total). We estimated the fruit size of dispersed seeds by fitting regressions of fruit diameter to seed diameter in intact fruits. We were able to predict fruit diameter from seed diameter in 12 of the 13 populations, although the relationship was stronger in single‐seeded species than in multi‐seeded species. Seven of the 12 populations tested showed a significant difference in seed diameter among undispersed and dispersed seeds. However, our results showed no consistent pattern in fruit size preference by the New Zealand pigeon and did not support our hypothesis. The large‐bodied New Zealand pigeon is generally not gape limited and fruit size preferences appear to be independent of mean fruit size.     

Seed retention times in the New Zealand pigeon,

We offered ripe fruits of tawa (Beilschmiedia tawa), taraire (B. tarairi), and pūriri (Vitex lucens) to captive New Zealand pigeons (Hemiphaga novaeseelandiae) and recorded seed retention times. We also recorded seed retention times while radio-tracking wild pigeons in Taranaki and Canterbury. We report wild pigeon retention times for tawa, pūriri, miro (Prumnopitys ferruginea), fivefinger (Pseudopanax arboreus), and kahikatea (Dacrycarpus dacrydioides) seeds. Where data were available for the same plant species from wild and captive pigeons, retention times were similar. Seed retention time differed significantly among fruit species, and was positively related to seed mass. Mean retention times ranged from 37-45 min for the two smallest-seeded species (fivefinger and kahikatea) up to 109-181 min for the three largest species (pūriri, taraire, and tawa). We also report the second published instance of regurgitation by the New Zealand pigeon.     

Methods of Measuring the Proportions of Plant-Species Present in Forest and Their Effect on Estimates of Bird Preferences for Plant-Species

Stem density, basal area, vegetation cover and vegetation surface area were compared as measures of the proportions of plant species present in North Okarito Forest, South Westland, for use in determining bird preferences for plant species. In general, stem density estimates of the proportions of canopy species were about 10 times lower than basal area estimates. The converse was true for estimates of the proportions of sub- canopy and understorey species. The proportions estimated from vegetation cover and vegetation surface area were similar for most species, and were intermediate between the proportions estimated from stem density and basal area. However, in the upper forest tiers, vegetation cover gave lower estimates for the proportions of canopy species and higher estimates for the proportions of sub-canopy species than given by vegetation surface area. These differences affect calculation of bird preferences for plant species. We recommend vegetation surface area as a measure of the proportional availability of plant species to birds because it is appropriate to most birds in New Zealand forests, is likely to be more accurate than visual estimates of vegetation cover, and can be measured on the same plots separately for trunks, branches, foliage, and fruit.     

Bird species diversity and abundance before and after eradication of possums and wallabies on Rangitoto Island, Hauraki Gulf, New Zealand

Five-minute bird counts were made on Rangitoto Island in 1998 and 1999, 8 and 9 years after the start, and 1 and 2 years after the completion of a 7-year programme that resulted in eradication of the introduced brushtail possum (Trichosurus vulpecula) and brushtailed rock wallaby (Petrogale penicillata). These were compared with counts made in 1990 (immediately before the start of the programme), to assess whether bird species diversity and abundance had increased as a result of the eradications. The number of bird species detected in 1998/99 was similar to 1990. Five-minute counts of all species except silvereye (Zosterops lateralis) and tui (Prosthemadera novaeseelandiae) were also similar in 1998/99 to those in 1990. Silvereye and tui counts increased significantly. This is most likely a response to increased flowering of pohutukawa (Metrosideros excelsa) and rewarewa (Knightia excelsa) as a result of possum (and wallaby) eradication. The most likely reason for no apparent increase in the abundance of other bird species is the continued presence of predators, especially ship rats (Rattus rattus), cats (Felis catus), and stoats (Mustela erminea).     

Honeyeaters and the New Zealand forest flora: The utilisation and profitability of small flowers

New Zealand flowers are frequently considered unspecialised allowing easy access to pollen and nectar by a wide range of visitors. Most conform with a syndrome of insect pollination (entomophily). Pollination of forest flowers by birds has been described for a range of species whose flowers are morphologically ornithophilous. On Kapiti Island and Little Barrier Island, all three species of New Zealand honeyeaters have been described feeding on flowers currently assumed to be entomophilous or where the pollination system is unknown. The persistence and regularity of visits suggests that the birds are obtaining suitable rewards in the form of nectar and could be serving as pollinators. We measured the nectar energetic value from flowers of three ornithophilous and five entomophilous species. Nectar production over 24 hours was highest in ornithophilous species, but the standing crop of nectar overlapped—ornithophilous species: Metrosideros fulgens (standing crop 6.6 J), Metrosideros excelsa (22 J), and Fuchsia excorticata (1.8 J); and entomophilous: Pittosporum crassifolium (23 J), Pseudopanax arboreus (1.5 J), Dysoxylum spectabile (3.7 early flowers -6.7 J late flowers), Pittosporum eugenioides (2.7 J) and Geniostoma rupestre (1.8 J). The entomophilous species present the flowers in aggregation and as result birds can visit a large number flowers per minute. We found that the average estimated nectar consumption rate for all the entomophilous species except G. rupestre was enough to sustain the two smaller New Zealand honeyeaters (hihi energy requirements= 0.12 kJ min(-1), median energy obtained: 0.16 kJ min(-1) D. spectabile—0.57 kJ min(-1) P. crassifolium); bellbird energy requirements = 0.10 kJ min(-1), median energy obtained: 0.14 kJ min(-1) D. spectabile—0.68 kJ min(-1) P. crassifolium). However, we estimate that if the birds are able to selectively forage on the flowers with most nectar, the energetic returns of all species may be sufficient for hihi and bellbird (hihi: 0.18 kJ min(-1) G. rupestre—0.93 kJ min(-1); P. crassifolium; bellbird: 0.12 kJ min(-1) G. rupestre 1.11 kJ min(-1) P. crassifolium). If tui (energy requirements: 0.25 kJ min(-1), forages randomly, only P. crassifolium (0.80 kJ min(- 1)) and D. spectabile late in the season (0.30 kJ min(-1)) provide sufficient returns, but if selective, P. arboreus (0.45 kJ min(-1)) may also suffice. We suggest that because (a) the nectar produced by entomophilous flowers provides sufficient energy to sustain the energetic requirements of birds, and (b) these plants flower in the cooler months when insect activity is reduced, birds might have played a wider role in pollination than previously considered. This finding is of particular importance because the abundance of New Zealand honeyeaters on the mainland has decreased considerably since human colonisation and this could be affecting forest regeneration.     

A pragmatic approach to characterising insect communities in New Zealand: Malaise trapped beetles

The dispersal, germination and establishment of the New Zealand Loranthaceae (Alepis flavida, Peraxilla colensoi, P. tetrapetala, Ileostylus micranthus and Tupeia antarctica) were investigated. The most important bird dispersers were tui, bellbirds and silvereyes. These birds appear to provide reasonably good quality dispersal: fruits were swallowed whole and the seeds later defecated in germinable condition; birds tended to visit plants for only 1-2 minutes and eat a few mistletoe fruits each time. Germinability of seeds ranged between species from moderate to high (17-96%). None of the study species of mistletoe germinated successfully unless the fruit skin (exocarp) was removed, by hand or by passage through a bird gut. While hand removal of the exocarp gave the same or higher percentage germination as bird removal, in the field bird dispersal is the only effective method of exocarp removal and is therefore essential. Dispersal was limiting at one of three sites studied (Craigieburn), suggesting that reductions in bellbird densities by introduced carnivores or competition for honeydew food sources may be indirectly affecting mistletoe reproduction. Establishment and survival of seedlings on host branches was low (15-28% depending on species to production of first independent leaves, 0-14% after two years). Survival of adults over one year of the study was 80% for Tupeia and 91-95% in the other species, showing that frequent establishment of seedlings is necessary for population maintenance. While disperser limitation does not seem to currently be a major threat to mistletoe survival, it must be considered as a possible factor both historically and in the future.     

Wing noises,wing slots,and aggression in New Zealand honeyeaters (Aves: Meliphagidae)

Abstract

Two of New Zealand’s honeyeaters, the tui (Prosthemadera novaeseelandiae) and the bellbird (Anthornis melanura) can produce loud wing noises. In both species, modified primary feathers form slots in the wing that presumably make these noises. The slots of bellbirds are similar to those of hummingbirds (Trochilidae). Asymmetries in aggressiveness — as determined from inter- and intraspecific dominance — are closely related to the presence or size of the wing slots.     

Tūhoe Tuawhenua mātauranga of kererū (

Indigenous peoples? knowledge on changes in wildlife populations and explanations for these changes can inform current conservation and wildlife management systems. In this study, Tūhoe Tuawhenua interviewees provided mātauranga (traditional knowledge) about a repertoire of visual (e.g. decreasing flock size), audible (e.g. less noise from kererū in the forest canopy), and harvest-related (e.g. steep decline in harvests since the 1950) indicators used to assess kererū (New Zealand pigeon; Hemiphaga novaeseelandiae novaeseelandiae) abundance and condition in Te Urewera, New Zealand over the last 100 years. Metaphorical explanations for the decline in kererū included the loss of mana (authority and prestige) by the iwi (tribe) over the kererū and forest, and the retraction of the kererū?s mauri (life force) by Tāne Mahuta (God of the Forest). Interviewees reported that predation and interspecific competition with introduced species, variability in food supply, and loss of habitat were the principal biophysical mechanisms to have caused declines in kererū abundance. Long-term qualitative monitoring by Tūhoe Tuawhenua has the potential to guide the restoration of kererū and wider environmental management in Te Urewera. Allowing iwi the self-determination to make management decisions according to their mātauranga (or science, if desired) is likely to lead to greater application of results and altered practices where required for sustainability.     

Breeding variation in female kakapo (

We investigated why some mature females of New?Zealand?s critically endangered parrot, the kakapo (Strigops habroptilus), did not attempt to breed during the 2005 breeding season on Codfish Island. At a population level, the initiation of kakapo breeding appears to correspond with years of mast fruiting of rimu (Dacrydium cupressinum) trees, with the proportion of females that breed each season dependent on the quantity of rimu fruit available. This research investigates possible links between habitat quality within individual home ranges and the breeding status of adult females during 2005, when the abundance of available rimu fruit was low. We assessed the importance of both home range size and habitat characteristics in determining breeding attempts. Foraging home ranges were characterised using radio-tracking and triangulation techniques. The relative importance of habitat variables in optimal breeding habitat was assessed using ecological niche factor analysis. Our results show that female kakapo breeding in 2005 had, on average, home ranges twice the size of those females that did not breed that season and the ranges contained a significantly greater quantity of mature rimu forest. Multivariate analysis illustrates female kakapo were effectively partitioning available habitat, as breeders? foraging locations were positively correlated with high-abundance rimu forest with a tall canopy, described as optimal breeding habitat. In contrast non-breeders? locations were weakly correlated with short forest containing little or no mature rimu forest. To maximise reproductive output each breeding season, conservation managers need to ensure that all breeding-aged females occupy optimal breeding habitat on Codfish Island. Removal to other islands of kakapo not required in the breeding population may enable females to increase their home range size and occupy better breeding habitat.     

Responses of kukupa (

The kukupa or New Zealand pigeon (Hemiphaga novaeseelandiae) is gradually declining on the New Zealand mainland, due mostly to predation by introduced pest mammals including ship rats (Rattus rattus) and brushtail possums (Trichosurus vulpecula). We report on a co-operative project between Maori landowners, the Department of Conservation, and Manaaki Whenua–Landcare Research researchers to restore a Northland kukupa population and to examine kukupa nesting success in relation to pest abundance. Ship rats and possums were targeted by trapping and poisoning throughout Motatau Forest (350 ha) from 1997 to 1999; only possums were targeted in 2000. All 13 kukupa nests located before pest control started in late 1997 failed at the egg stage, but all seven nests located in 1998–99 successfully fledged young when trapping and tracking indices of possums and ship rats were less than 4%. After pest control, counts of kukupa and some other bird species increased at Motatau compared with counts in a nearby non-treatment block, suggesting numbers of adult kukupa can be increased in small forest areas by intensive pest control. This increase is due at least partly to increased nest success. Evidence from time-lapse video cameras, sign remaining at nests, and nest success rates under different pest control regimes suggest both ship rats and possums are important predators at kukupa nests.     

Foods and Foraging of Forest Birds in Temperate Rain-Forest, South Westland, New Zealand

Habitat use of a forest bird community was studied in temperate rainforests in South Westland, New Zealand between 1983 and 1985. This paper examines foraging methods, feeding stations and seasonal variations in the availability and use of food types and provides a brief review of the subject. The forest bird community was comprised of a large number of apparently generalist feeders and few dietary specialists. However, the degree of foraging specialisation should not be viewed only in relation to the food types consumed. The 18 species studied differed from each other in the number of plant species used, their preferred feeding stations and method of feeding. Most importantly, the omnivorous birds exhibited varying degrees of sequential specialisation in their diets as they switched between specific food sources from season to season. The information on foraging provides the first step towards predicting the impacts of logging important food trees.     

Assessing the Success of Restoration Plantings in a Temperate New Zealand Forest

The success of restoration plantings in restoring indigenous forest vascular plant and ground invertebrate biodiversity was assessed on previously grass-covered sites in the eastern South Island, New Zealand. The composition and structure of grassland, three different aged restoration plantings (12, 30, and 35 years old), a naturally regenerating forest (100 years old), and a remnant of the original old-growth forest of the area were measured. The restoration plantings are dominated by the native tree Olearia paniculata, which is not indigenous to the study area. Despite this, indigenous forest invertebrate and plant species are present in all three restoration sites and with increasing age the restoration sites become compositionally more similar to the naturally regenerating and mature forest sites. In particular the regenerating vegetation of the restoration sites is very similar floristically to the regenerating vegetation of the naturally regenerating and mature forest sites, despite marked differences in the current canopy vegetation reflecting the presence of the planted O. paniculata. The presence of regeneration in all three restoration sites indicates that the functional processes that initiate regeneration, such as dispersal, are present. The majority of regenerating tree species (71%) are bird dispersed and it is clear that birds play an important role in the recolonization of plant species at these sites despite the absence of edible fruit attractive to frugivorous birds on O. paniculata, a wind-dispersed species. The strong correlations between plant and invertebrate community composition and study-site age (r = 0.80, ?0.24, ?0.68 for plants, beetles, and spiders, respectively) suggest that the restoration site plant and invertebrate communities are undergoing change in the direction of the naturally regenerating and mature forest communities. Without restoration, colonization of grassland by forest plants is very slow in the study area and the restoration plantings studied here have been successful because they have considerably accelerated the return to forest at these sites.     

Birds and small mammals in kanuka (

Native kanuka (Kunzea ericoides) and adventive gorse (Ulex europaeus) stands aged 10-14 years, and not grazed by domestic stock, were studied near Nelson, New Zealand. The aim was to determine their use by introduced small mammals, and native and adventive birds, and the effects of these animals on seed rain and seedling dynamics as factors influencing vegetation succession. Seed traps were established where they could catch only bird-dispersed or wind-blown seed, and seedling emergence and growth were monitored. Bird abundance was estimated by five-minute bird counts, and small mammal abundance by trapping. The summed frequencies of all birds, and those likely to disperse seeds, were similar in kanuka and gorse. The endemic native bird species, bellbirds (Anthornis melanura) which are omnivorous, brown creepers (Mohoua novaeseelandiae) and grey warblers (Gerygone igata) which are insectivorous, were more frequent in kanuka than in gorse, while fantails (Rhipidura fuliginosa) were equally frequent in both stands. Non-endemic silvereyes (Zosterops lateralis) which are omnivorous were the most abundant seed-dispersing species, and they were significantly more frequent in gorse, as were adventive California quail (Callipepla californica) which are granivorous. Other small adventive granivores and omnivores were either more frequent in kanuka or gorse, or equally common in both stands. Ship rats (Rattus rattus) and possums (Trichosurus vulpecula) were in low numbers throughout. Mice (Mus domesticus) were more frequent in the gorse, probably because of the shelter offered by the dry gorse litter, and food supply, e.g. gorse seed. More seeds of native, fleshy-fruited shrubs fell in the kanuka, largely those of Coprosma spp. and Cyathodes juniperina, which grow in the kanuka. Seed species richness was similar in kanuka and gorse. In both cases, the seed rain appeared more influenced by the local seed source than by the different bird communities. In both kanuka and gorse, the relationship between seed rain and seedling numbers was close only for the most common fleshy-fruited species. Seedling emergence and survival was greater in gorse because of openings in the canopy, and the lower density of the introduced hares and rabbits. Overall, the different morphology and structure of the adventive gorse probably have the greatest influence in seedling dynamics, and ultimately on vegetation succession.     

Population structure and biogeography of Hemiphaga pigeons (Aves: Columbidae) on islands in the New Zealand region

Aim The New Zealand avifauna includes lineages that lack close relatives elsewhere and have low diversity, characteristics sometimes ascribed to long geographic isolation. However, extinction at the population and species levels could yield the same pattern. A prominent example is the ecologically important pigeon genus Hemiphaga. In this study, we examined the population structure and phylogeography of Hemiphaga across islands in the region. Location New Zealand, Chatham Islands and Norfolk Island. Methods Mitochondrial DNA was sequenced for all species of the genus Hemiphaga. Sixty‐seven individuals from mainland New Zealand (Hemiphaga novaeseelandiae novaeseelandiae), six of the Chatham Islands sister species (Hemiphaga chathamensis), and three of the extinct Norfolk Island subspecies (Hemiphaga novaeseelandiae spadicea) were included in this study. Novel D‐loop and cytochrome b primers were designed to amplify DNA from museum samples. Additionally, five other mitochondrial genes were used to examine placement of the phylogenetic root. Results Analyses of mitochondrial DNA sequences revealed three Hemiphaga clades, consistent with the allopatric populations of recognized (sub)species on oceanic islands. Of the 23 D‐loop haplotypes among 67 New Zealand pigeons (Hemiphaga n. novaeseelandiae), 19 haplotypes were singletons and one haplotype was common and widespread. Population genetic diversity was shallow within and between New Zealand populations, indicating range expansion with high inter‐population exchange. Tentative rooting of the Hemiphaga clade with cyt b data indicates exchange between mainland New Zealand and the Chatham Islands prior to colonization of Norfolk Island. We found low genetic divergence between populations on New Zealand, the Chatham Islands and Norfolk Island, but deep phylogenetic divergence from the closest living relatives of Hemiphaga. Main conclusions The data are consistent with the hypothesis of population reduction during the Pleistocene and subsequent expansion from forest refugia. Observed mobility of Hemiphaga when feeding helps explain the shallow diversity among populations on islands separated by many hundreds of kilometres of ocean. Together with comparison of distribution patterns observed among birds of the New Zealand region, these data suggest that endemicity might represent not long occupancy of an area, but descent from geologically recent colonizations. We consider the role of lineage pruning in creating the impression of old endemicity.     

Controlling small mammal predators using sodium monofluoroacetate (1080) in bait stations along forestry roads in a New Zealand beech forest

A single five night pulse of sodium monofluroacetate (0.15% 1080) applied in bait stations at two different spacing intervals, 100 and 200 m, along forestry roads in New Zealand beech forest, killed all four of the resident radio-tagged stoats (Mustela erminea) and all three of the resident radio- tagged wild house cats (Felis catus) by secondary poisoning. Gut contents of predators indicated that house mice (Mus musculus), ship rats (Rattus rattus) and bushtail possums (Trichosurus vulpecula) were important sources of the toxin. High kills of predators, possums and rats at both 100 and 200 m spacing regimes suggest that greater efficacy of controlling these pests would be achieved with the latter method. Evidence suggests that routine management of possums and rats using 1080 and brodifacoum has resulted in widespread control of small mammalian carnivores by secondary poisoning in New Zealand forests. However, aerial application of poison can kill large numbers of tomtits (Petroica macrocephala) and robins (Petroica australis) and few other native bird species have been adequately monitored through such operations. Reducing risks to native wildlife is responsible ecological management. Use of bait stations along forestry roads or tracks may be fundamental in mounting cost-effective :Large-scale ground-based protection of native wildlife through safer predator controls.     

An evaluation of the efficiency of rodent trapping methods: The effect of trap arrangement, cover type, and bait

Anticoagulant poisons were laid within native forest at Wenderholm Regional Park (near Auckland) to reduce rat numbers during the summer months. Snap trapping indices and an artificial nest experiment confirmed the high potential for rat interference in unpoisoned forest patches outside Wenderholm, compared with the near-zero potential at Wenderholm. Over two breeding seasons, 70 New Zealand pigeon (Hemiphaga novaeseelandiae) nests were located and monitored. Nest predation was significantly lower at Wenderholm than in non- treatment areas, but hatching and fledging success were not significantly different, due to a high level of nest desertion at Wenderholm. Possums (Trichosurus vulpecula) were found to be nest predators, and their low numbers at Wenderholm confounded the results of the rat poisoning experiment.     

Review of South-Island High Country Land Management Issues-Joint Submission to the Ministerial High Country Review Committee from the New Zealand Ecological Society and the New Zealand Society of Soil Science

Recent work at several central South Island sites has shown that the bird-pollinated mistletoe Peraxilla tetrapetala (Loranthaceae) is extensively pollen-limited. We studied the diet, time-budget, and densities of its principal pollinator, bellbirds (Anthornis melanura, Meliphagidae), at Craigieburn to find out what aspect of bellbird ecology may be limiting pollination. Direct observations of bellbird diets showed that they are annual generalists on invertebrates (diet range 22-85% of food items) and honeydew (diet range 2-45%), and concentrate seasonally on mistletoe fruit (18-60%) and mistletoe nectar (27-58%) when available. The bellbirds at Craigieburn are more insectivorous than New Zealand's other two honeyeaters (tui and stitchbirds). In general, bellbirds are most similar to the short-billed guild of Australian honeyeaters in their beak morphology, foraging behaviour, and diet choice, but with a greater importance of fruit in the bellbird diet. The annual mean number of bellbirds recorded per 5-minute count (1.05) at Craigieburn was relatively low, even compared to other eastern South Island sites, which have lower counts of bellbirds than the western South Island and offshore islands. As mistletoe fruit and nectar were preferred foods when in season, and bellbird counts were low at Craigieburn, we conclude that it is the probable low number of bellbirds in the area, and not their choice of diet, which limits mistletoe pollination and dispersal. The bellbird population at Craigieburn did not appear to be food limited as bellbirds spent less than 20% of their time feeding, and the number of hours per day bellbirds spent feeding and foraging did not change significantly from winter to summer while food resources became more plentiful. Other pressures that limit the bellbird population size, particularly predation from introduced mammals, would appear more likely explanations for poor pollination and disperser services to mistletoes at Craigieburn.